Five questions heading into 49ers' preseason finale vs. Chargers

SANTA CLARA — MarQueis Gray never has been cut from a football team, but the rookie tight end is on the bubble to make the 49ers' final roster that must be pared to 53 by Saturday.

"Any way I can open eyes and help the team gives me a little bit of hope," said Gray, a converted quarterback from the University of Minnesota.

Thursday night's exhibition finale at San Diego offers one more chance for Gray and others to stick with the reigning NFC champions.

Gray has made a late surge among a tight end corps that features Vernon Davis, second-round draft pick Vance McDonald and Garrett Celek, the only undrafted rookie to make last year's final cut.

Gray (6-foot-4, 250 pounds) knows he has must vastly improve his blocking, footwork and hand placement. Because he's such a project, the 49ers might opt to send him to the practice squad.

Despite playing quarterback and wideout at Minnesota, Gray hasn't practiced at either position with the 49ers, who instead are seeing if he can fit into Delanie Walker's old role.

When Gray returned to Minnesota's campus before training camp, he visited the Gophers' tight ends coach to seek more tips on his position switch. Recalled Gray: "First thing he said is, 'How's Vernon Davis?' And I said, 'Coach, I'm doing good, too.'

"I know I can't stay complacent," Gray added. "I see veteran guys getting cut. This isn't college anymore. No scholarships." With 22 players on the chopping block, here are five intriguing battles to watch in the exhibition finale: 1. Who's the No. 3 quarterback? Every team would love this question for the finale, because it means your starter (Colin Kaepernick) emerged healthy through three exhibitions and your top backup has been determined (Colt McCoy).

Rookie B.J. Daniels should see his most extensive action as he tries to secure the No. 3 job over newcomer Seneca Wallace.

2. Which outside linebacker can help the 49ers forget Parys Haralson, who was traded to New Orleans earlier in the week?

Dan Skuta likely will be the 49ers' third outside linebacker, filling in for Ahmad Brooks or Aldon Smith in the base defense. Corey Lemonier has had a terrific exhibition season and looks like a bona fide pass rusher. Cam Johnson has had a couple of nifty moments, too, but he could be ticketed for another practice-squad stint.

3. How does Joe Looney play after a questionable hit?

After not playing as a rookie, Looney found the national spotlight (but no NFL fine) with Sunday's block into Viking Kevin Williams' knee. Looney insisted he meant no harm but added that he's doing all he can to make the roster. The 2012 fourth-round pick likely is a lock to serve as the eighth offensive lineman, but keep an eye on how he plays.

4. Which defensive backs win reserve roles?

Rookie Eric Reid will start at free safety in Week 1, joining strong safety Donte Whitner and cornerbacks Carlos Rogers and Tarell Brown. But who will be their backups? Nnamdi Asomugha looks to have won the No. 3 job, so where does that leave Tramaine Brock, Perrish Cox and rookies Marcus Cooper and Darryl Morris? Could Cooper unseat a veteran? At safety, the 49ers must debate among Craig Dahl, C.J. Spillman, Trenton Robinson and Michael Thomas, as well as special-teams ace Bubba Ventrone.

Special-teams contributions ultimately could answer all the questions.

5. Could this be Brian Jennings' finale?

Every special-teams snap since 2000 has come off Jennings' trustworthy hands. But rookie Kevin McDermott has thrust himself into what Jim Harbaugh calls an even competition. Jennings' streak of 208 consecutive games is tied for first in franchise history with tackle Len Rhode.